NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2025-11-06 | 628-329 | 9XXX which blocks → | T-MOBILE USA, INC. | 6529 | SAUSALITO | CA |
| 2024-09-25 | 628-315 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX9XXX · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | BELVEDERE | CA |
| 2024-08-30 | 628-312 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2024-07-30 | 628-308 | 0XXX1XXX2XXX3XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC MT-EV | CA |
| 2024-07-30 | 628-309 | 0–9 XXXwhole prefix which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2024-05-31 | 628-306 | 0–9 XXXwhole prefix which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2024-05-22 | 628-305 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | SAN RAFAEL | CA |
| 2024-05-01 | 628-304 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC JUNPR | CA |
| 2024-04-03 | 628-310 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | BELVEDERE | CA |
| 2024-03-06 | 628-301 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | NOVATO | CA |
| 2024-03-06 | 628-302 | 0XXX1XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | CORTEMADRA | CA |
| 2024-02-29 | 628-298 | 0–9 XXXall 10 · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC JUNPR | CA |
| 2024-02-21 | 628-297 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC MT-EV | CA |
| 2023-07-13 | 628-290 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC JUNPR | CA |
| 2022-01-07 | 628-283 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC MT-EV | CA |
| 2021-11-03 | 628-313 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | SAN RAFAEL | CA |
| 2021-01-11 | 628-276 | 0–9 XXXall 10 · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2019-09-30 | 628-269 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | SAN RAFAEL | CA |
| 2018-12-05 | 628-264 | 0–9 XXXall 10 · 2 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2017-10-19 | 628-258 | 0–9 XXXall 10 · 7 holders which blocks → | T-MOBILE USA, INC. | 6529 | NICASIO | CA |
| 2016-12-01 | 628-213 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
| 2016-07-01 | 628-204 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | NICASIO | CA |
| 2016-07-01 | 628-241 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC JUNPR | CA |
| 2016-07-01 | 628-252 | 0–9 XXXall 10 · 5 holders which blocks → | T-MOBILE USA, INC. | 6529 | CORTEMADRA | CA |
| 2016-04-01 | 628-202 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | BELVEDERE | CA |
| 2016-03-04 | 628-237 | 0–9 XXXall 10 · 4 holders which blocks → | T-MOBILE USA, INC. | 6529 | SAUSALITO | CA |
| 2016-02-04 | 628-236 | 0–9 XXXall 10 · 6 holders which blocks → | T-MOBILE USA, INC. | 6529 | NOVATO | CA |
| — | 628-358 | 0–9 XXXall 10 · 3 holders which blocks → | T-MOBILE USA, INC. | 6529 | SNFC CNTRL | CA |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.